UK GAS-Prompt prices dip on mild weather, oversupply

* System oversupplied by 19 mcm/day

* Temperatures seen holding above normal for 10 days

April 14 (Reuters) - British prompt gas prices slipped on Tuesday as mild weather and ample supply weighed.

Gas for day-ahead delivery was trading down 0.2 percent at 47.65 pence per therm by 0904 GMT, while gas for within-day delivery was down 1.6 percent at 47.35 pence per therm.

Meteorologists at Thomson Reuters Point Carbon forecast temperatures holding above normal levels for the coming 10 days.

National Grid (LSE: NG.L - news) data showed supply was forecast at 210 million cubic metres (mcm) on Tuesday while demand was seen at 191 mcm, showing the system was oversupplied by 19 mcm.

"Prompt prices are down due to unseasonably warm weather, with tomorrow forecast to be the hottest day of the year so far," said Wayne Bryan, analyst at consultancy Alfa Energy, adding that the system was comfortably supplied.

"Gas demand has also been reduced by wind generation, which is contributing 12 percent of UK power at present."

Gas exports to Britain from Western Europe's top gas supplier, Norway, were steady from the previous day. Norway's total gas production capacity has been cut by more than 140 mcm per day since Friday because of planned maintenance at the Troll and Kvitebjoern fields.

Further along the curve, gas for delivery next month was up 0.3 percent at 46.75 pence per therm.

In the Netherlands, the day-ahead gas price at the TTF hub was up 1.3 percent at 22.63 euros per megawatt-hour.

A Dutch court plans to issue a provisional ruling on Tuesday in a lawsuit challenging the government's gas production policy at the Groningen field.

The benchmark European Union carbon price was trading 0.3 percent lower at 6.82 euros a tonne on ICE Futures Europe. (Reporting by Sarah McFarlane; Editing by David Goodman)